An aircraft has a skid rail and a tail skid on a bottom surface of a fuselage as parts for protecting the aircraft fuselage from damage when the aircraft comes into contact with a runway, etc. If the skid rail were totally worn by belly-landing, a carry-through tank would not be sufficiently protected, necessitating the skid rail to have sufficient wear resistance. The skid rail and the tail skid are conventionally formed by glass-fiber-reinforced plastics. For instance, JP 2000-344196 A proposes a retractable, wear-resistant tail skid for aircrafts, which has a roller pad formed by a glass-fiber-reinforced plastic at its tip end. However, the glass fiber-reinforced plastic does not have sufficient wear resistance.
Because the glass fiber-reinforced plastics have insufficient wear resistance, it would be conceivable to form the entire skid rail by, for instance, plastics reinforced by high-wear-resistant fibers such as poly(p-phenylenebenzobisoxazole) fibers. However, because such high-wear-resistant fiber-reinforced plastics have low machinability, it is extremely difficult to provide skid rails formed thereby with recesses or holes for fasteners.